From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: [PATCH v4 20/29] tools/libxl: Convert a legacy stream if needed Date: Tue, 14 Jul 2015 11:59:35 +0100 Message-ID: <1436871584-6522-21-git-send-email-andrew.cooper3@citrix.com> References: <1436871584-6522-1-git-send-email-andrew.cooper3@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1436871584-6522-1-git-send-email-andrew.cooper3@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Xen-devel Cc: Andrew Cooper , Ian Jackson , Ian Campbell , Wei Liu List-Id: xen-devel@lists.xenproject.org For backwards compatibility, a legacy stream needs converting before it can be read by the v2 stream logic. This causes the v2 stream logic to need to juggle two parallel tasks. check_all_finished() is introduced for the purpose of joining the tasks in both success and error cases. Signed-off-by: Andrew Cooper CC: Ian Campbell CC: Ian Jackson CC: Wei Liu --- v4: Alter logic layout in check_all_finished() v3: Simplified greatly from v2. No practical change. --- tools/libxl/libxl_internal.h | 2 ++ tools/libxl/libxl_stream_read.c | 66 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 68 insertions(+) diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h index 97755fe..b65019b 100644 --- a/tools/libxl/libxl_internal.h +++ b/tools/libxl/libxl_internal.h @@ -3258,12 +3258,14 @@ struct libxl__stream_read_state { libxl__ao *ao; libxl__domain_create_state *dcs; int fd; + bool legacy; void (*completion_callback)(libxl__egc *egc, libxl__stream_read_state *srs, int rc); /* Private */ int rc; bool running; + libxl__conversion_helper_state chs; /* Main stream-reading data. */ libxl__datacopier_state dc; /* Only used when reading a record */ diff --git a/tools/libxl/libxl_stream_read.c b/tools/libxl/libxl_stream_read.c index 2eb4ff5..4b677f6 100644 --- a/tools/libxl/libxl_stream_read.c +++ b/tools/libxl/libxl_stream_read.c @@ -86,6 +86,10 @@ * - stream_write_emulator() * - stream_write_emulator_done() * - stream_continue() + * + * Depending on the contents of the stream, there are likely to be several + * parallel tasks being managed. check_all_finished() is used to join all + * tasks in both success and error cases. */ /* Success/error/cleanup handling. */ @@ -93,6 +97,10 @@ static void stream_complete(libxl__egc *egc, libxl__stream_read_state *stream, int rc); static void stream_done(libxl__egc *egc, libxl__stream_read_state *stream); +static void conversion_done(libxl__egc *egc, + libxl__conversion_helper_state *chs, int rc); +static void check_all_finished(libxl__egc *egc, + libxl__stream_read_state *stream, int rc); /* Event chain for first iteration, from _start(). */ static void stream_header_done(libxl__egc *egc, @@ -151,6 +159,7 @@ void libxl__stream_read_init(libxl__stream_read_state *stream) { stream->rc = 0; stream->running = false; + libxl__conversion_helper_init(&stream->chs); FILLZERO(stream->dc); FILLZERO(stream->hdr); LIBXL_STAILQ_INIT(&stream->record_queue); @@ -165,6 +174,7 @@ void libxl__stream_read_start(libxl__egc *egc, libxl__stream_read_state *stream) { libxl__datacopier_state *dc = &stream->dc; + STATE_AO_GC(stream->ao); int rc = 0; libxl__stream_read_init(stream); @@ -172,6 +182,29 @@ void libxl__stream_read_start(libxl__egc *egc, stream->running = true; stream->phase = SRS_PHASE_NORMAL; + if (stream->legacy) { + /* Convert the legacy stream. */ + libxl__conversion_helper_state *chs = &stream->chs; + + chs->ao = stream->ao; + chs->legacy_fd = stream->fd; + chs->hvm = + (stream->dcs->guest_config->b_info.type == LIBXL_DOMAIN_TYPE_HVM); + chs->completion_callback = conversion_done; + + rc = libxl__convert_legacy_stream(egc, &stream->chs); + + if (rc) { + LOG(ERROR, "Failed to start the legacy stream conversion helper"); + goto err; + } + + assert(stream->chs.v2_carefd); + stream->fd = libxl__carefd_fd(stream->chs.v2_carefd); + stream->dcs->libxc_fd = stream->fd; + } + /* stream->fd is now a v2 stream. */ + dc->ao = stream->ao; dc->readfd = stream->fd; dc->writefd = -1; @@ -545,6 +578,10 @@ static void stream_done(libxl__egc *egc, if (stream->emu_carefd) libxl__carefd_close(stream->emu_carefd); + /* If we started a conversion helper, we took ownership of its carefd. */ + if (stream->chs.v2_carefd) + libxl__carefd_close(stream->chs.v2_carefd); + /* The record queue had better be empty if the stream believes * itself to have been successful. */ assert(LIBXL_STAILQ_EMPTY(&stream->record_queue) || stream->rc); @@ -552,6 +589,35 @@ static void stream_done(libxl__egc *egc, LIBXL_STAILQ_FOREACH_SAFE(rec, &stream->record_queue, entry, trec) free_record(rec); + check_all_finished(egc, stream, stream->rc); +} + +static void conversion_done(libxl__egc *egc, + libxl__conversion_helper_state *chs, int rc) +{ + libxl__stream_read_state *stream = CONTAINER_OF(chs, *stream, chs); + + check_all_finished(egc, stream, rc); +} + +static void check_all_finished(libxl__egc *egc, + libxl__stream_read_state *stream, int rc) +{ + STATE_AO_GC(stream->ao); + + if (!stream->rc && rc) { + /* First reported failure. Tear everything down. */ + stream->rc = rc; + + libxl__stream_read_abort(egc, stream, rc); + libxl__conversion_helper_abort(egc, &stream->chs, rc); + } + + /* Don't fire the callback until all our parallel tasks have stopped. */ + if (libxl__stream_read_inuse(stream) || + libxl__conversion_helper_inuse(&stream->chs)) + return; + stream->completion_callback(egc, stream, stream->rc); } -- 1.7.10.4